The Instacart CEO told Fortune the U.S. healthcare system is not well-suited to treat rare and complex diseases, which is a major opportunity for AI.

The woman behind Instacart’s successful IPO, Fidji Simo, is joining OpenAI’s C-suite. On Wednesday, OpenAI CEO Sam Altman announced Simo’s new role as CEO of Applications. She will report directly to him after transitioning out of her current role at Instacart later this year.

With her new leadership role at OpenAI, Fidji Simo will be expected to bring to bear everything she’s learned about building customer loyalty — and navigating internal drama.